(Reuters) - U.S. first lady Melania Trump's airplane returned to the Joint Base Andrews military facility in Maryland after experiencing a "minor mechanical issue" on Wednesday, the first lady's spokeswoman Stephanie Grisham said in an emailed statement.

About 15 minutes after takeoff, the plane's cabin started filling with smoke and there was a smell of something burning, according to a separate statement from White House pool reporters who were on board.

A flight crew member gave passengers damp towels to hold over their faces for the smell, the reporter said.

The plane landed shortly after 9:00 a.m. EDT (1300 GMT).

"Everything is fine and everyone is safe," Grisham said.

The first lady, health and human services secretary Alex Azar and others on the trip were transferred to a second plane, the media pool statement said.

The plane was supposed to land in Philadelphia, where Trump was scheduled to visit Thomas Jefferson University Hospital and meet with families affected by prenatal opioid use as part of her "Be Best" campaign.